January in Yokosuka averages a daily high of 10.3°C. Expect roughly 4.7 wet days totalling 49.2mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Yokosuka is April–June.
Based on YOKOHAMA, JA (16.7km), 1995–2024. 27 years of January data.